Pliers



Dec. 8, 1970 PATRICK v r 5 31 PLIERS Filed July 1968 INVENTOR ATTORNEY United States Patent 3,545,316 PLIERS Frank Patrick, Meadville, Pa., assignor to Channellock, Inc., Meadville, Pa., a corporation of Pennsylvania Filed July 11, 1968, Ser. No. 744,189 Int. Cl. B2511 7/12 US. Cl. 81-368 6 Claims ABSTRACT OF THE DISCLOSURE The shock of releasing toggle pliers is reduced by a stop on the release lever which engages one of the toggle links when the knee of the toggle passes from the pressure to the opening side of dead center. The effect is a two stage release where the heavy pressure is dissipated before the parts are allowed to move to the fully released position. In a preferred form, the release lever is pivoted to the actuating level and has a stop engaging the toggle link associated with the actuating lever to arrest the parts at the first stage of release.

This invention is intended to reduce the shocks which accompany release of the gripping pressure in toggle or vise grip pliers. In a preferred form Where the release is effected by a release lever which is pivoted on the actuating lever and which has a stop engaging the toggle link associated with the release lever to limit the initial or first stage of release to the point at which the toggle links move from dead center to the release side of dead center and the heavy closing pressure of the jaws of the work is released. Since the movement of the jaws at this stage is slight, the momentum of the parts is small even though the pressures which are released are huge. During the second stage, the release lever is moved clear of the toggle link and a spring moves the actuating lever to its fully released position in readiness to receive another work plece.

In the drawing, FIG. 1 is a side elevation of toggle pliers in the closed position, FIG. 2 is a side elevation showing the actuating lever moved to the pressure release side of dead center, and FIG. 3 is a side elevation showing the pliers in the fully released position.

'In FIGS. 1 and 2 the two stage opening is shown in connection with the pliers of the type shown in Pat. 2,997,903, this showing being by way of example and not of limitation. As there shown, the handle 1 has a fixed jaw 2 at one end and at the other end has a generally rectangular section 3 which is mounted a tiltable locking slide 4 which is biased to the right as viewed in FIG. 1 by a tension spring 5 connected between point 6 on the slide and point 7 on a movable jaw 8 pivoted at 9 on the handle 1. The effect of the spring 5 is to close-the jaw 8 on the stationary jaw 2 with an initial pressure which is determined by the tension of the spring 5. The jaw can be opened by grasping the slide 4 in the region indicated by the numeral 10 and sliding it backward or to the left as viewed in FIG. 1. Upon release of the slide, the spring 5 will automatically close the jaws of the work under light pressure. The position of the slide 4 is automatically adjusted to correspond with the thickness of the work between the jaws 2, 8. This eliminates the need for manual adjustment of the pliers to fit the thickness of the work. The full gripping pressure is developed by an actuating lever 11 of channel section pivoted at 12 on the movable jaw 8 and pivoted at 13 on a link 14 pivoted at 15 to the lower end of the slide 4. The pivot 15 is offset far enough from the center of the slide 4 so that a force from the link 14 to the left as viewed in FIG. 1 tilts the slide through an angle sufficient to cause the slide to lock upon the handle section 3. As the actuating lever 11 is moved toward the closed position shown in FIG. 1 by squeezing the hand grip section 11a of lever 11 toward the handle 1, the pivot pin 13 which constitutes the knee or common pivot of the toggle is moved to the dead center or full pressure position in which the pivots 12, 1'3 and 15 lie on a common center line. In this position, a stop or projection 16 on the link 14 engages the bottom wall of the actuating lever 11. From one point of view, the slide 4 constitutes an adjustable abutment for toggle link 14.

The gripping pressure between the jaws is released by a release lever 17 of channel section pivoted on the actuating lever 11 by pivot 18.

When the release lever is squeezed toward the handle 1, it fulcrums at 19 on the slide 4 and pries the actuating lever 11 away from the handle 1 and moves knee or common pivot 13 of the toggle to the release side of dead center. As the knee moves to the release side of dead center, the full gripping pressure between the jaws is released and unless restrained could accelerate the movable parts to high speeds causing objectionable shock. This is prevented by a catch 20 on the release lever which engages a surface 21 and positively limits the first stage of release of jaw pressure to the point at which the toggle would continue its movement toward the released position without further assistance from the release lever 17. At this stage, the pressure between the jaws is substantially released but the jaws have not substantially opened. The momentum to be absorbed is accordingly small. The catch surface 21 is shown as being on toggle link 14 but could be on slide 4 or any other part related to the link 14. From FIG. 2 it can be seen that so long as release lever 17 is held, further movement of the actuating lever 11 away from the handle 1 is not possible.

The second stage of pressure release is efiected by release of the hand grip portion of the release lever 17, permitting the spring 5 to move the actuating lever 11 to the full release position shown in FIG. 3. Since the motion of the second stage of release takes place under the action of spring 5, the forces are relatively small compared to those developed during the initial stage of pressure release.

What is claimed is:

1. In a plier type toggle wrench having a handle With a stationary jaw at its front end, a movable jaw pivoted to said front end of the handle, toggle means for forcing the movable jaw toward the stationary jaw including an actuating lever having one end pivoted to the movable jaw and the other end with a hand grip section spaced from and opposite the back end of the handle, an adjustable abutment on the handle, a toggle link having one end pivoted to the abtument and the other end pivoted to the actuating lever between its ends, the movable jaw being forced toward the stationary jaw by squeezing the hand grip section of the actuating lever toward the handle to bring the common pivot between the actuating lever and the toggle link into dead center relation with the other pivots, a release lever pivoted on the actuating lever for prying the hand grip section of the actuating lever away from the handle to bring said common pivot to the release side of dead center remote from the handle, said release lever having a catch engaging a cooperating catch element in substantially fixed relation to the handle as the common pivot moves to said release side of dead center to arrest the momentum of the toggle means.

2. The structure of claim 1 in which the cooperating catch element is on said toggle link.

3. The structure 'of claim 1 in which spring means between the abutment and the movable jaw urges the movable jaw toward the stationary jaw.

4. The structure of claim 1 in which the catch enages the cooperating catch element when the pressure between the jaws is substantially released but prior to substantial opening of the jaws.

5. The structure of claim 1 in which the pliers includes spring means urging the actuating lever away from the handle a further distance after engagement of the catch and catch element whereby upon release of the release lever after such engagement, the actuating lever effects a 5 further release of pressure between the jaws.

6. The structure of claim 5 in which the spring means is connected between the abutment and the movable jaw and causes movement of the jaws to the closed position and movement of the actuating lever to the released position.

References Cited UNITED STATES PATENTS 9/1958 Petersen 81 370X 8/1961 Rommel et a1 81-372X 

